磁流变弹性体若干物理量的数值分析

应用有限元方法,考虑了颗粒的磁化饱和过程与非线性磁化过程,计算得到了磁流变弹性体中的磁场分布,进而研究了在不同磁场大小、不同颗粒体积比浓度下磁流变弹性体在成链方向的相对磁导率,计算结果和实验结果取得了一致。利用Maxwell应力张量,计算了磁场引起的磁流变弹性体的附加剪切模量。分析了颗粒体积比浓度、外加磁场对磁流变弹性体的磁致剪切模量的影响。研究了颗粒为旋转椭球形状时,颗粒的放置方式与其长短轴之比对磁流变弹性体的磁致剪切模量的影响。计算结果表明,磁流变弹性体的相对磁导率随颗粒体积比浓度的增大而增大,随磁场强度的增大而减小,颗粒的形状和放置方式对磁流变效应有很大的影响。

Simulation on physical parameters of magneto-rheological elastomers

By means of finite element method where the nonlinearity and saturation of the particle magnetization were incorporated,the distribution of magnetic field inside MR(Magneto-Rheological) elastomers was obtained when they were exposed to an external magnetic field.Then the relative magnetic permeabilities of the MR elastomers in the direction of the chain-like structures were also calculated for various magnetic fields and particle volume fractions.The results are in agreement with that of experiments.Using Maxwell stress tensor,a model was proposed to calculate the increase in the shear modulus due to the magnetic field for the MR elastomers.The influences of the particle concentration and applied magnetic field on the increments in the shear modulus due to the magnetic field were analyzed.When the particles were rotary ellipsoid,the influences of the way how the particles were arranged and the ratio of the long axis to the short axis on the magnetic-induced shear modulus were studied.Results show that,the relative magnetic permeability of the MR elastomers increases with the particle concentration,but decreases when the magnetic field increases.The shape and arrangement of the particles have significant influence on the magneto-rheological effect.